1. Field of the Invention
The present invention relates to a control of an autonomous traveling vehicle.
2. Description of the Related Art
There are known an autonomous traveling vehicle or robot that autonomously travels along a traveling route while reproducing the route taught by a user. For instance, JP-A-8-326025 discloses a cleaning robot, which includes a casing equipped with a travel drive unit for traveling on a floor surface, a position detector for detecting a position of the casing on the floor surface, a cleaning unit for cleaning the floor surface, an operation receiving unit for receiving operation inputs for the travel drive unit and the cleaning unit, a storage unit to store a traveling route based on positions detected by the position detector in association with received content of the operation receiving unit, and a controller for reading stored content stored in the storage unit and controlling the travel drive unit and the cleaning unit based on the stored content.
This cleaning robot includes drive wheels and travel motors connected directly to the drive wheels so as to rotate the drive wheels disposed on left and right sides in a middle portion of a bottom surface of the casing. Further, by differentiating rotation speeds of the left and right travel motors, the cleaning robot can turn left and right. In this way, the minimum turning radius is able to be reduced so that cleaning work is able to be efficiently performed. Such a traveling unit, including the left and right pair of drive wheels and the travel motors connected directly to the drive wheels so as to rotate the drive wheels, may be referred to as an opposed two-wheel differential type traveling unit.
In the traveling unit (traveling portion) like the opposed two-wheel differential type traveling unit of the cleaning robot disclosed in JP-A-8-326025, in which rotation speeds or the like of the wheels are independently controlled for changing direction, an optimal value of a control parameter to control the rotation speeds of the wheels may be different between a case where the cleaning robot travels straight (or substantially straight) and a case where the cleaning robot changes the direction.
For instance, in a travel cart (autonomous traveling vehicle) that autonomously travels along a traveling route taught by a user, when the control parameter is set to an optimal value for straight travel, the autonomous traveling vehicle may not be able to travel faithfully along the taught traveling route. It is because that when the autonomous traveling vehicle tries to change the direction, the rotation speeds of the wheels of the traveling unit may not be controlled so that the autonomous traveling vehicle changes the direction as intended. In this case, the autonomous traveling vehicle is not able to travel by faithfully reproducing the taught traveling route in an autonomous travel mode.